The Middle Fork of the Salmon is not so much a river as an exuberant expression of water at play. It tumbles and turns and trips over itself for a hundred miles through the largest unbroken wilderness in the lower 48, the 2.3-million-acre Frank Church-River of No Return Wilderness, named for the pristine Salmon River gorge and the Idaho senator who made sure most of its vast watershed would stay that way. No dams temper its flow. No roads line its banks. It dances down its canyon much as it has since the glaciers receded 10,000 years ago-in spring as a raging, tree-felling torrent, in late summer as a spare, crystalline rivulet.
Today it is one of the ultimate white-water experiences in the United States, drawing thousands of visitors each year. But 60 years ago its future-and that of hundreds of other rivers across the country-looked very different. For much of the 20th century, the federal government seemed determined to dam virtually all the major rivers in the country, harnessing their power for electricity, irrigation, navigation, water supply, and flood control. The dam binge was particularly acute in the arid West, where even the Grand Canyon was slated for flooding. The Army Corps of Engineers evaluated five prospective dam sites on the Middle Fork alone. The river would have morphed into a chain of man-made lakes if two brothers hadn't helped stem the tide of concrete.
All of these images and others can be found in the November 2011 issue of National Geographic magazine, on newsstands October 25.
All photos and captions courtesy of National Geographic.